Metaphor is used here. The previous sentence compares people who have no deep learning foundation to reeds, which will only sway with the wind and echo everywhere. The latter sentence compares those who rely on the old and have no real talent to bamboo shoots, which is superficial and flashy.

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When Jie Jin was a child prodigy, he was young and famous. Once I met a senior official, the old gentleman was not convinced. He thinks you are so famous at an early age and how much you can do. So I deliberately made things difficult for him. On the surface, he described the growth state of reed. In fact, he taught Jie Jin a lesson with puns. Don't be too frivolous at an early age. You should know that there are people outside the mountain.

Unexpectedly, Jie Jin is not a fuel-efficient lamp, so I immediately came to the second part, which means don't look at the age of your beard. There is no real skill, and the old man is choking and coughing.

However, this pair has been handed down to later generations, and its image description and profound pun make people never tire of reading it, leaving their lips and teeth fragrant.